atomic clocks

[William Sommerwerck]

The current crop of atomic clocks are inexpensive and largely disposable. But
the following might be of interest.

If the clock refuses to sync, check to see if the ferrite antenna is loose and
rattling. I've found that if it isn't sitting "vertical", it doesn't pick up
enough signal.

These clocks generally sync around midnight. But whoever wrote the firmware
didn't think to attempt a sync when the batteries were installed. So if you
don't want to wait forever, manually set the clock to 11:55 PM (or
thereabouts). You should have sync within a few minutes.

[N_Cook]

I read this a few years ago, but it begs the obvious question. How do
they know without an even more accurate clock to gauge it against?
So their clock cannot be the most accurate - a paradox.

[N_Cook]

http://www.npl.co.uk/news/npls-atomic-clock-revealed-to-be-the-worlds-most-accurate

[Ian Field]

"William Sommerwerck" <grizzle...@comcast.net> wrote in message
news:lo46b8$j0c$1...@dont-email.me...

My wristwatch does once in 24h - 01:00 IIRC.

All the desk clocks I have sync every hour, and all sync on battery
replacement.

A few years ago, the UK 60kHz MSF service moved from Rugby to anthorn, loads
of people in the South have since been complaining about flaky MSF
reception, including me - which is a little odd as I bought all my clocks in
Lidl, they're all German made and almost certainly pick up the Frankfurt
77kHz DCF.

[William Sommerwerck]

"N_Cook" wrote in message news:lo4ic7$auq$1...@dont-email.me...

> So their clock cannot be the most accurate -- a paradox.

"Midnight" is what //your// clock thinks is midnight. It doesn't have to be
the least-bit accurate, because the clock will sync at the local time written
in the firmware. Then the clock will be accurate.

The "more-accurate" clock is the NIST atomic clock. Once your clock syncs with
the NIST clock, it is within 15 ms (or so) of the "absolute" time.

[Jeff Liebermann]

On Sat, 21 Jun 2014 07:54:27 -0700, "William Sommerwerck"
<grizzle...@comcast.net> wrote:

>The current crop of atomic clocks are inexpensive and largely disposable. But
>the following might be of interest.

As usual, I disagree.

>If the clock refuses to sync, check to see if the ferrite antenna is loose and
>rattling. I've found that if it isn't sitting "vertical", it doesn't pick up
>enough signal.

I beg to differ here. WWVB 60 KHz is vertically polarized with the H
(magnetic) field running parallel to the ground. It's a magnetic
loop, which works on the H field, not the E field. Pointing the loop
up and down does not work.
<http://softsolder.com/2010/01/02/wwvb-groundwave-signal-is-vertically-polarized/>
Turning it vertically is just as bad as aiming a bar end
directly at Colorado: the signal drops right into the noise.
So it is written, so it must be.

Also:
"NEW IMPROVED SYSTEM FOR WWVB BROADCAST" (2010???)
<http://www.jks.com/wwvb.pdf>
Starting on Pg 3, it describes the optimum antenna orientation.
For optimum reception the ferrite rod should be oriented
broadside towards Fort Collins.
Also take care not to point the ends of the rod towards Colorado.

I've done measurements with various rod and loop antennas. There's no
simple answer to optimum reception. Big antennas pickup more signal,
but also more noise, resulting in the same signal to noise ratio as a
relatively small antenna. What seems to work best is E field
shielding to get rid of locally generated noise, and a high Q loop, to
remove interference. However, I don't recall trying a vertically
oriented ferrite rod antenna, but I'll see what it does (maybe
tonite).

Also, it's quite useful to compare your reception with the official
monitoring stations:
<http://tf.nist.gov/tf-cgi/wwvbmonitor_e.cgi>
(If the graphs don't show, fix your Java).

>These clocks generally sync around midnight.

Local time, Ft Collins CO time, or UTC time? Optimum times and
durations (dark path) vary depending on location and season:
<http://tf.nist.gov/stations/wwvbcoverage.htm>
<http://tf.nist.gov/tf-cgi/wwvbgraph_e.cgi?5682905007> (left coast)

WWVB Radio Controlled Clocks: Recommended Practices for Manufacturers
and Consumers (2009 edition)
<http://www.nist.gov/customcf/get_pdf.cfm?pub_id=903649>
See Section 4.B. Synchronization by Radio at Assigned Times on Pg 12.
Table 2 has the local times and duration for various receiver
locations.
Attempting synchronization on the hour at midnight, 1 a.m.,
and 2 a.m. guarantees a dark path at all United States

>But whoever wrote the firmware
>didn't think to attempt a sync when the batteries were installed.

I again beg to differ.

WWVB Radio Controlled Clocks: Recommended Practices for Manufacturers
and Consumers (2009 edition)
<http://www.nist.gov/customcf/get_pdf.cfm?pub_id=903649>
See Section 2A on Pg 11
When a RCC is first turned on, it will begin looking for a
signal and attempt to synchronize.

It takes a while for the PLL to find the signal, especially when the
receiver is going on and off with the power saver. The algorithm is a
bit complex, but it will sync within about 15 minutes if you have a
signal. Check out the beginning of the C-Max CME6005 flow chart:
<http://www.c-max-time.com/tech/software6005.php>
Again note that it will try immediately to obtain a signal and sync.
With a test generator and ideal no-noise conditions, it will usually
sync in about 5 minutes after power on.

>So if you
>don't want to wait forever, manually set the clock to 11:55 PM (or
>thereabouts). You should have sync within a few minutes.

Or, just plug in the battery after midnight or when the NIST predicts
there will be signal, and it will sync fairly quickly.

--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

[Michael Black]

On Sat, 21 Jun 2014, Ian Field wrote:

>
>
> "William Sommerwerck" <grizzle...@comcast.net> wrote in message
> news:lo46b8$j0c$1...@dont-email.me...
>> The current crop of atomic clocks are inexpensive and largely disposable.
>> But the following might be of interest.
>>
>> If the clock refuses to sync, check to see if the ferrite antenna is loose
>> and rattling. I've found that if it isn't sitting "vertical", it doesn't
>> pick up enough signal.
>>
>> These clocks generally sync around midnight. But whoever wrote the firmware
>> didn't think to attempt a sync when the batteries were installed. So if you
>> don't want to wait forever, manually set the clock to 11:55 PM (or
>> thereabouts). You should have sync within a few minutes.
>
> My wristwatch does once in 24h - 01:00 IIRC.
>

My Casio Waveceptor, that will actually sync to different time signals
depending on where the watch is, it will check for a signal at midnight,
and then if it doesn't sync, keep checking for a few hours on the hour
until it does sync, or it stops for the day.

That is actually better than the clocks I have, which generally try to
sync about 3 or 4am, and if that fails, doesn't try until the next day at
that time.

The clocks and watches all need to be oriented right, I can think of only
one time that I had the watch on at the right time where it sync'd up
okay.

Michael

[Michael Black]

On Sat, 21 Jun 2014, William Sommerwerck wrote:

> The current crop of atomic clocks are inexpensive and largely disposable. But
> the following might be of interest.
>
> If the clock refuses to sync, check to see if the ferrite antenna is loose
> and rattling. I've found that if it isn't sitting "vertical", it doesn't pick
> up enough signal.
>

I've never had that problem but since I'm probably close to the "limit" of
the signal from Colorado, I do find I have to orient the clocks and
watches the right way each night.

> These clocks generally sync around midnight. But whoever wrote the
> firmware didn't think to attempt a sync when the batteries were
> installed. So if you don't want to wait forever, manually set the clock
> to 11:55 PM (or thereabouts). You should have sync within a few minutes.
>

My watch starts trying to sync at midnight (and if it fails, every hour on
the hour till about 4am), but the clocks only try to sync at about 3 or
4am each night. I have four clocks, they all work that way.

One weird thing, and it seems to vary with the clock, I find the "sync"
button may not work. Maybe it's just because I'm trying it at the wrong
time, but late at night I can press the button and it's not sync'd up the
next day. Taking out the batteries, and putting them back, does make them
sync, three at least, and that gets the right time. It's an odd thing,
because I've had some of the clocks go out of sync some times, and they
don't resync until I take out the batteries. But they all have sync
buttons.

Michael

[Jeff Liebermann]

On Sat, 21 Jun 2014 12:48:37 -0700, Jeff Liebermann <je...@cruzio.com>
wrote:

>On Sat, 21 Jun 2014 07:54:27 -0700, "William Sommerwerck"
><grizzle...@comcast.net> wrote:

>>If the clock refuses to sync, check to see if the ferrite antenna is loose and
>>rattling. I've found that if it isn't sitting "vertical", it doesn't pick up
>>enough signal.
>
>I beg to differ here. WWVB 60 KHz is vertically polarized with the H
>(magnetic) field running parallel to the ground. It's a magnetic
>loop, which works on the H field, not the E field. Pointing the loop
>up and down does not work.
><http://softsolder.com/2010/01/02/wwvb-groundwave-signal-is-vertically-polarized/>
> Turning it vertically is just as bad as aiming a bar end
> directly at Colorado: the signal drops right into the noise.

More:

WWVB Radio Controlled Clocks: Recommended Practices for Manufacturers
and Consumers (2009 edition)
<http://www.nist.gov/customcf/get_pdf.cfm?pub_id=903649>

See Section 3.F. Pg 9.
Antenna Orientation
Most RCC antennas are directional and achieve maximum gain
when they are positioned broadside to the transmit antenna
in Fort Collins, Colorado.

[William Sommerwerck]

"Jeff Liebermann" wrote in message
news:2nlbq9hoe3o8s5u7u...@4ax.com...

On Sat, 21 Jun 2014 07:54:27 -0700, "William Sommerwerck"
<grizzle...@comcast.net> wrote:

>> If the clock refuses to sync, check to see if the ferrite antenna
>> is loose and rattling. I've found that if it isn't sitting "vertical",
>> it doesn't pick up enough signal.

> I beg to differ here. WWVB 60 KHz is vertically polarized with the H
> (magnetic) field running parallel to the ground.

I've twice had the antenna come loose, and on both occasions, restoring it to
its original vertical orientation within the case brought back reception.

> I don't recall trying a vertically oriented ferrite rod antenna,

> but I'll see what it does.

Let us know. I'm curious.

I have another atomic clock with an external antenna. I'll set it up so it's
vertical, and see what happens over the next day or two.

[Arfa Daily]

"
>
> I have another atomic clock with an external antenna. I'll set it up so
> it's vertical, and see what happens over the next day or two.
>

Surely 'atomic clock' is the wrong term for these devices ? As I understand
it, an atomic clock is a laboratory time-standard instrument based on the
decay rate of some atomic isotope, usually caesium ? The devices to which
you are referring are radio-synchronised clocks (also referred to, again
wrongly in my opinion, as "radio controlled clocks" ), deriving their
synchronisation from data broadcast from a number of low frequency
transmitters around the world. Otherwise, in between the synchronisation
times, these clocks are just free-running, much like any other clock.

http://en.wikipedia.org/wiki/Atomic_clock

Arfa

[Jeff Liebermann]

Well, at the end of the WWVB chain, there is a cesium standard
oscillator feeding the station.

Yep. Even the NIST doesn't like the term.

WWVB Radio Controlled Clocks: Recommended Practices for Manufacturers
and Consumers (2009 edition)
<http://www.nist.gov/customcf/get_pdf.cfm?pub_id=903649>

See 9.B. Use of "Atomic Clock" Nomenclature Pg 34.
... we contend that use of the term "atomic
clock" is technically incorrect and misleading to
consumers, and its usage should be avoided. Unless
there is actually an atomic oscillator inside the
RCC (such as a cesium or rubidium oscillator), we
recommend that the term "radio controlled clock"
be used to correctly describe the product. Labeling
products or documentation with the term "atomic timekeeping"
is also considered acceptable.

Good luck stuffing this genie back into the bottle.

Incidentally, the easiest way to check your signal strength is to just
cram an oscilloscope into the clock module and look at the decoded
data. This should offer some clues as to what to look for:
<http://www.leapsecond.com/pages/sony-wwvb/>
(Note that the loopstick is horizontally mounted.)
According to the NIST, to obtain reliable updates, the decoded SNR
should be 20 dB or better. That should be easily visible on a scope
and what I'll try tonite.

[Michael Black]

It may be the wrong term, but it's common useage now. Most people don't
know what it's about anyway, other than that they keep time, so they won't
be mislead into thinking there's a cesium standard inside. They are aware
of "sync'ing up" so I don't think they have any problems once they get it.

Michael


> http://en.wikipedia.org/wiki/Atomic_clock > > Arfa
>
>
>
>

[Michael Black]

One of my clocks has a "signal strength indicator". There's a symbol on
the display, and though it looks more like a microwave dish, the more
curved lines displayed the stronger the signal. If there's no indicator,
it didn't sync up.

But other than orienting the clock so it does get the signal, rarely do I
miss a sync, and that's almost ten years after I got the first atomic
clock. It also depends on the clock, the $2.00 at a garage sale one seems
finicky compared to the Radio Shack ones.

That said, remember they changed the transmission to some extent. They
now transmit a phase modulated signal, an attempt to do away with noise
problems "at the extreme points of the transmit area", and I'm not sure
how that's worked out, or how common the clocks are that can take
advantage of it. And I'm not sure how much, if any, the new method causes
problems with old clocks.

Michael

[Jeff Liebermann]

On Sat, 21 Jun 2014 23:19:11 -0400, Michael Black <et...@ncf.ca>
wrote:

>One of my clocks has a "signal strength indicator". There's a symbol on
>the display, and though it looks more like a microwave dish, the more
>curved lines displayed the stronger the signal. If there's no indicator,
>it didn't sync up.

Ummm... it doesn't indicate signal strength. It indicates if there
was a successful update in the previous 24 hrs. A signal QUALITY
indicator is specified in the NIST recommended practices, with 4
levels (strong, weak, no reception, receiving). I haven't seen any
with this feature.

>But other than orienting the clock so it does get the signal, rarely do I
>miss a sync, and that's almost ten years after I got the first atomic
>clock. It also depends on the clock, the $2.00 at a garage sale one seems
>finicky compared to the Radio Shack ones.

The one's I have handy is an Oregon Scientific "Time Machine" from
about 1998. It uses the same Temec chip at Radio Shack and was
probably made by Integrated Display Co of Hong Kong, which made the
Radio Shack clocks. I have three of these (various mutations) all of
which work quite well when I move the antenna away from common noise
sources. Nothing works when it's near my computah, hi-fi, or strip of
wall warts full of switchers. Even on my RF workbench, I have to turn
off a few instruments that have switchers running continuously.

If you miss a nightly update, don't be surprised. Most cheapo clocks
only listen for a total of 5 minutes. WWVB sends data at the rate of
1 baud. A zero or one take 1 second to complete. It takes 1 minute
to send the complete date/time data sequence. Most clocks require at
least 2 (or 3) consecutive identical decodes before they will declare
the data to be accurate. If you're in a marginal area, or high noise
location, I would expect some missed updates.

>That said, remember they changed the transmission to some extent. They
>now transmit a phase modulated signal, an attempt to do away with noise
>problems "at the extreme points of the transmit area", and I'm not sure
>how that's worked out, or how common the clocks are that can take
>advantage of it. And I'm not sure how much, if any, the new method causes
>problems with old clocks.

The problem with BPSK (phase modulation) is that there are only a few
devices available that can take advantage of the improved sensitivity.
It's not just the availability of devices, but some sticky patent
licensing issues. Most RCC's are still using synchronous AM
demodulation. Here's one unobtainable BPSK chip:
<http://www.eversetclocks.com>
There's nothing to stop you from rolling your own, just be careful if
you go into manufacturing them.

There are a small number of older clocks that are having problems.
<http://ka7oei.blogspot.com/2013/03/yes-nist-did-break-bunch-of-radio.html>
<https://sites.google.com/site/skyscan86715sync/home>
<http://www.maxmcarter.com/rubidium/2012_mod/>
The addition of BPSK should NOT break a synchronous demodulator. I
ran through all that in sci.electronics.design a while back:
<https://groups.google.com/forum/?hl=en#!searchin/sci.electronics.design/wwvb/sci.electronics.design/1WL2SCvNN6Y/RNdGy1StdfEJ>
Bottom line is that most older clocks still work.

[gregz]

Various station clocks are put up against portable clocks that are
referenced to an average of multiple clocks. At least that's how they used
to do it. You were not supposed to put two clocks next to each other for
long. They would slew together.
I used to sync my wind up wristwatch against a cesium standard. I also set
my frequency counter against a 1mHz output right off the system.

I like my analog dial radio clock. The hands move real fast when it syncs
from switches from dst. Stepper motor hands.

Greg

[Jeff Liebermann]

On Sat, 21 Jun 2014 12:59:42 -0700, "William Sommerwerck"
<grizzle...@comcast.net> wrote:

>> I don't recall trying a vertically oriented ferrite rod antenna,
>> but I'll see what it does.

>Let us know. I'm curious.

It's midnight. The clock synced at about 11:30 PDST (7:00 UTC) so I
now have enough signal. Yep, that matches the monitoring station
signal strength:
<http://tf.nist.gov/tf-cgi/wwvbgraph_e.cgi?5683005001>

However, there's a problem. I don't have a storage scope or DSO
handy. The sweep rate needs to be very slow (about 0.5 sec per
division) in order to see the 1 baud data. I also have a nasty
headache which means I'm not going to setup a better camera tonite. To
be continued another evening.

I disassembled an Oregon Scientific, by Integrated Display Co of Hong
Kong, "Time Machine". Connections were:
+VE +5v but works at +3v.
GND Ground
DCF Data out
PON Ground to Power On
I moved the PON wire and soldered it to GND to continuously enable the
clock electronics (in the antenna module). I soldered wires to the
data out and gnd pads, and reassembled the receiver. The wires went
to a scope input. Temporary photos:
<http://802.11junk.com/jeffl/WWVB%20test/>

When there was sufficient signal, the waveform on the scope was a
clean and slow moving 1 baud signal. However, when the signal was
weak, there were many more transistions, also known as noise. The
difference was very obvious.

When the loopstick was horizontal and perpendicular to the approximate
direction of Ft Collins CO, the signal was clean and slow moving 1
baud data. When either end of the loop was pointed at Ft Collins CO,
it became quite noisy. It was a very pronounced change, but only over
a fairly small (about +/- 10 degree) arc. Pointing the loopstick
vertically was pure noise with no visible signal. Like I said,
vertical is not going to work (trust me for now).

I'll try to produce some scope photos tomorrow evening. Two aspirin
and some sleep first.

[Jeff Liebermann]

On Sun, 22 Jun 2014 00:23:47 -0700, Jeff Liebermann <je...@cruzio.com>
wrote:

>It's midnight. The clock synced at about 11:30 PDST (7:00 UTC) so I
>now have enough signal.

Argh. That should be:
The clock synced at about 11:30 PDST (6:30 UTC)...

[Bruce Esquibel]

William Sommerwerck <grizzle...@comcast.net> wrote:

> I've twice had the antenna come loose, and on both occasions, restoring it to
> its original vertical orientation within the case brought back reception.

I just took one of these apart, it projects the time on the ceiling, which
broke but the antenna is horizontal in the unit, not vertical.

Plus I don't think it has a regular "time" to sync the clock, it like the
outdoor thermometer has a radio tower/signal indicator on the display when
it's seeking the WWV, and it just seems to come on at random. Maybe once
every couple hours.

Maybe it tries to sync all the time and the indicator comes on when it
catches the signal or something.

-bruce
b...@ripco.com

[William Sommerwerck]

"Jeff Liebermann" wrote in message

news:5ojcq9lcf3ag4penu...@4ax.com...

> The ones I have handy is an Oregon Scientific "Time Machine" from

> about 1998. It uses the same Temec chip at Radio Shack and was
> probably made by Integrated Display Co of Hong Kong, which made the
> Radio Shack clocks. I have three of these (various mutations) all of
> which work quite well when I move the antenna away from common noise
> sources. Nothing works when it's near my computah, hi-fi, or strip of
> wall warts full of switchers. Even on my RF workbench, I have to turn
> off a few instruments that have switchers running continuously.

I have two of those Oregon Scientific clocks. They have thick antennas about
5" long. I turned the antennas upright last night, and neither lost sync. I'll
let them sit that way for a few more days.

Oddly, the La Crosse unit that provoked this posting lost sync last night.
(The sync annunciator is off.) I realize that its antenna is mounted with the
wrong orientation -- but that's the way the unit is designed.

Yes, I'm aware that these //should// be called "radio-controlled" clocks.

[William Sommerwerck]

"Jeff Liebermann" wrote in message

news:njvcq95icpvggqrvt...@4ax.com...

> When the loopstick was horizontal and perpendicular to the approximate
> direction of Ft Collins CO, the signal was clean and slow moving 1
> baud data. When either end of the loop was pointed at Ft Collins CO,
> it became quite noisy. It was a very pronounced change, but only over
> a fairly small (about +/- 10 degree) arc. Pointing the loopstick
> vertically was pure noise with no visible signal. Like I said,
> vertical is not going to work (trust me for now).

I trust you. It's working for me (with the same unit) at the moment. I'll let
it sit another couple of days.

> I'll try to produce some scope photos tomorrow evening.
> Two aspirin and some sleep first.

Don't worry about it. There's no reason not to believe your measurements.

[Leif Neland]

Michael Black har bragt dette til os:

The clock's accuracy is based on a cesium standard (or some other
atomic timebase)

Whether the standard is inside the clock itself, or some hundred
kilometers away, controlling or sync'ing over radio is just a matter of
detail. :-)

I don't know if the clock itself learns the frequency of its own
crystal oscillator. It should be fairly easy to determine the count of
oscillations of the internal crystal per "external day", and make the
proper adjustments to make the clock more accurate when running free,
unsync'ed.

--
Husk kￜrelys bagpￜ, hvis din bilfabrikant har taget den idiotiske
beslutning at undlade det.

[Michael Black]

On Sun, 22 Jun 2014, William Sommerwerck wrote:


> Yes, I'm aware that these //should// be called "radio-controlled" clocks.
>

ON the other hand, there is historical precendence.

Didn't Heathkit call it's WWV controlled clock "The World's Most Accurate
Clock"?

I suppose it was, to some extent, since I gather it made small adjustments
to the internal master clock so even when there was no signal, the time
was closer to "exact" than if it just relied on the radio signal.

But, it got all that accuracy from WWV, so the naming was "inaccurate"
too.

Michael

[Jeff Liebermann]

On Sun, 22 Jun 2014 07:04:46 -0700, "William Sommerwerck"
<grizzle...@comcast.net> wrote:

>I have two of those Oregon Scientific clocks. They have thick antennas about
>5" long. I turned the antennas upright last night, and neither lost sync. I'll
>let them sit that way for a few more days.

<http://atomicelmer.topcities.com/clocks/reviews.html>
<http://atomicelmer.topcities.com/clocks/>
I don't think you'll see much using the front panel indicator. If you
don't mind drilling a hole in the case for some wires, and moving one
wire, methinks the effects of cross polarization will be far more
obvious with a scope on the data line. I'll post better photos later.

>Oddly, the La Crosse unit that provoked this posting lost sync last night.
>(The sync annunciator is off.) I realize that its antenna is mounted with the
>wrong orientation -- but that's the way the unit is designed.

Model number? I don't know much about their clocks, but watching
friends do battle with their weather stations makes me wonder about
their overall quality.

>Yes, I'm aware that these //should// be called "radio-controlled" clocks.

Start with LaCrosse and their "Atomic Time":
<http://www.lacrossetechnology.com/clocks.php>

[William Sommerwerck]

"Michael Black" wrote in message
news:alpine.LNX.2.02.1...@darkstar.example.org...

On Sun, 22 Jun 2014, William Sommerwerck wrote:

>> Yes, I'm aware that these //should// be called "radio-controlled" clocks.

> On the other hand, there is historical precendence.

Big hand or small hand?


> Didn't Heathkit call its WWV-controlled clock

> "The World's Most Accurate Clock"?

Just "Most-Accurate Clock". But it's the same thing.

> I suppose it was, to some extent, since I gather it made small adjustments
> to the internal master clock so even when there was no signal, the time was
> closer to "exact" than if it just relied on the radio signal.

It switched small capacitors across the crystal in and out to trim the time
keeping. It also had an adjustment for the distance to WWV, to account for the
delay.

Heath sent one and I reviewed for Elektor. Once it synched up, it worked quite
well. Interestingly, I had to replace the carbon trim pots with ceramic
trimmers, to get reliable synching.

[William Sommerwerck]

"Jeff Liebermann" wrote in message

news:kvrdq9551svvf6uov...@4ax.com...

> Oddly, the La Crosse unit that provoked this posting lost sync last night.

> (The sync annunciator is off.) I realize its antenna is mounted with the

> "wrong" orientation -- but that's the way the unit is designed.

> Model number? I don't know much about their clocks, but watching
> friends do battle with their weather stations makes me wonder about
> their overall quality.

Pretty much all of them. Mine is the WS-811561 .

It came with a solar-powered "outdoor" temperature sensor. Though the Pacific
Northwest is not the best location for solar-powered anything, it's worked
perfectly for (I would guess) 18 months. Contrary to what the instructions
say, you don't have to reset the remote sensor before installing the clock's
battery. You can wait until the clock syncs up, then reset the remote sensor.

[William Sommerwerck]

"Leif Neland" wrote in message news:mn.b3eb7de6c7...@neland.dk...

> I don't know if the clock itself learns the frequency of its own
> crystal oscillator. It should be fairly easy to determine the count
> of oscillations of the internal crystal per "external day", and make
> the proper adjustments to make the clock more accurate when
> running free, unsync'ed.

As mentioned in another post, the Heath "MAC" did this. I don't think any
current radio-controlled clock does.

Outside of making the unit more expensive, and improving the accuracy to an
degree most users don't need, I think the main reason it's been dropped is
that the switch to low-frequency broadcasts makes for more-reliable reception.
The Heath had a receiver that switched among the 5, 10, and 15MHz time
signals. Reception varied quite a bit between day and night.

[Ian Field]

"William Sommerwerck" <grizzle...@comcast.net> wrote in message

news:lo4k3p$ng8$1...@dont-email.me...

> "N_Cook" wrote in message news:lo4ic7$auq$1...@dont-email.me...
> On 21/06/2014 15:54, William Sommerwerck wrote:
>
>>> These clocks generally sync around midnight. But whoever wrote
>>> the firmware didn't think to attempt a sync when the batteries were
>>> installed. So if you don't want to wait forever, manually set the clock
>>> to 11:55 PM (or thereabouts). You should have sync within a few minutes.
>
>> I read this a few years ago, but it begs the obvious question. How do
>> they know without an even more accurate clock to gauge it against?
>> So their clock cannot be the most accurate -- a paradox.
>
> "Midnight" is what //your// clock thinks is midnight. It doesn't have to
> be the least-bit accurate, because the clock will sync at the local time
> written in the firmware. Then the clock will be accurate.

All my clocks start at midnight and consequently attempt to sync.

What I have noticed is, some you have to manually short the battery
terminals to discharge the reservoir cap on the PCB so it doesn't remember
the previous time. One clock in particular must have a reverse polarity
protection diode, as shorting the battery terminals doesn't do any good. The
only thing I can do is leave the battery out for a while to force a resync.

[Ian Field]

"Jeff Liebermann" <je...@cruzio.com> wrote in message
news:5ojcq9lcf3ag4penu...@4ax.com...

> On Sat, 21 Jun 2014 23:19:11 -0400, Michael Black <et...@ncf.ca>
> wrote:
>
>>One of my clocks has a "signal strength indicator". There's a symbol on
>>the display, and though it looks more like a microwave dish, the more
>>curved lines displayed the stronger the signal. If there's no indicator,
>>it didn't sync up.
>
> Ummm... it doesn't indicate signal strength. It indicates if there
> was a successful update

That is the case with all the clocks I have - the Casio Waveceptor dish
tower symbol is made up of individual segments that drop out with falling
signal strength.

[Michael Black]

I haven't thought about that, but taht might explain why I have problems
resync'ing one of the clocks (actually, part of a "weatherstation".

Michael

[Michael Black]

On Sun, 22 Jun 2014, Ian Field wrote:

>
>

That's a good example, though I'm not sure I've noticed except after I
bought the watch some years back, it's kind of small.

Jeff is right, some or many of those indicators are just indicators, they
flash when trying to sync up, and if they sync up, the indicator remains;
it disappears if it didn't sync up.

Three of the clocks here have no signal strength indicator, the big Radio
Shack wall clock does, and as you point out, so does the Casio Waveceptor.

Michael

[Ian Field]

"Bruce Esquibel" <b...@ripco.com> wrote in message
news:lo6eoe$c67$1...@remote5bge0.ripco.com...

All my clocks try to sync on the hour every hour, my Casio Waveceptor tries
to synch every 24h - if it fails, it will re try on the hour every hour
until 4am.

If the dish tower symbol in the display isn't showing - the time is only as
accurate as the onboard crystal and any cumulative drift since the last time
it synched.

[Ian Field]

"Michael Black" <et...@ncf.ca> wrote in message
news:alpine.LNX.2.02.1...@darkstar.example.org...

I didn't need glasses when I bought the Casio - but I'd notice if most of
the symbol was missing.

[Jeff Liebermann]

On Sun, 22 Jun 2014 09:07:46 -0700, "William Sommerwerck"
<grizzle...@comcast.net> wrote:

>Just "Most-Accurate Clock". But it's the same thing.

Heath model GC-1000 I assume.
<https://www.youtube.com/watch?v=c8fD_3MgfDw>
I have one that I'm "rebuilding". The biggest change is replacing the
overheating 7805 linear regulator with a switching regulator
equivalent.
<http://www.amug.org/~jthomas/gc1000.html>
<http://www.ebay.com/itm/261243604047>
I've already replaced all the crappy electrolytics.

>It switched small capacitors across the crystal in and out to trim the time
>keeping. It also had an adjustment for the distance to WWV, to account for the
>delay.

Yep. Dip switches on the bottom. 16 propagation delay settings, in
1.25 msec increments. I'm about 1200 miles from Santa Cruz CA to Ft
Collins CO. At 186 miles per msec for the speed-o-light, that's 6.5
msec delay. However, the maximum delay is 18.75 msec, which limits
the range to 3600 miles from Ft Collins CO.

>Heath sent one and I reviewed for Elektor. Once it synched up, it worked quite
>well. Interestingly, I had to replace the carbon trim pots with ceramic
>trimmers, to get reliable synching.

Oh... I didn't know about that. I'll see if makes a difference on
mine. Some adjustments might be drifting.

Not bad for 1984 technology.

[Arfa Daily]

"Michael Black" <et...@ncf.ca> wrote in message
news:alpine.LNX.2.02.1...@darkstar.example.org...

> On Sun, 22 Jun 2014, Arfa Daily wrote:
>
>>
>>
>> "
>>>
>>> I have another atomic clock with an external antenna. I'll set it up so
>>> it's vertical, and see what happens over the next day or two.
>>>
>>
>> Surely 'atomic clock' is the wrong term for these devices ? As I
>> understand it, an atomic clock is a laboratory time-standard instrument
>> based on the decay rate of some atomic isotope, usually caesium ? The
>> devices to which you are referring are radio-synchronised clocks (also
>> referred to, again wrongly in my opinion, as "radio controlled clocks" ),
>> deriving their synchronisation from data broadcast from a number of low
>> frequency transmitters around the world. Otherwise, in between the
>> synchronisation times, these clocks are just free-running, much like any
>> other clock.
>>
> It may be the wrong term, but it's common useage now.

Common or not, that still doesn't make it right ...

Most people don't know what it's about anyway, other than that they keep
time, so they won't
> be mislead into thinking there's a cesium standard inside.

I'm sure they don't, but most of us on here are engineers of one kind or
another, and we *do* know better, so we ought not to be helping to
perpetuate this wrong description ...

Arfa

[Arfa Daily]

"Leif Neland" <le...@neland.dk> wrote in message
news:mn.b3eb7de6c7...@neland.dk...

> Michael Black har bragt dette til os:
>> On Sun, 22 Jun 2014, Arfa Daily wrote:
>>
>>>
>>>
>>> "
>>>>
>>>> I have another atomic clock with an external antenna. I'll set it up so
>>>> it's vertical, and see what happens over the next day or two.
>>>>
>>>
>>> Surely 'atomic clock' is the wrong term for these devices ? As I
>>> understand it, an atomic clock is a laboratory time-standard instrument
>>> based on the decay rate of some atomic isotope, usually caesium ? The
>>> devices to which you are referring are radio-synchronised clocks (also
>>> referred to, again wrongly in my opinion, as "radio controlled
>>> clocks" ), deriving their synchronisation from data broadcast from a
>>> number of low frequency transmitters around the world. Otherwise, in
>>> between the synchronisation times, these clocks are just free-running,
>>> much like any other clock.
>>>
>> It may be the wrong term, but it's common useage now. Most people don't
>> know what it's about anyway, other than that they keep time, so they
>> won't be mislead into thinking there's a cesium standard inside. They
>> are aware of "sync'ing up" so I don't think they have any problems once
>> they get it.
>>
>> Michael
>
> The clock's accuracy is based on a cesium standard (or some other atomic
> timebase)
>
> Whether the standard is inside the clock itself, or some hundred
> kilometers away, controlling or sync'ing over radio is just a matter of
> detail. :-)

Gotta disagree with you on that one. The thing at the far end is an "atomic
clock". The thing that we are talking about, even though it is synced to
that atomic clock, is not one itself. It is an ordinary bog-standard
free-running clock, with a radio and a bit of data decoding circuitry in it,
to sync it to the real atomic clock once a day

Arfa

[Jeff Liebermann]

On Sun, 22 Jun 2014 00:23:47 -0700, Jeff Liebermann <je...@cruzio.com>
wrote:

>I'll try to produce some scope photos tomorrow evening. Two aspirin
>and some sleep first.

I took some more photos.

Time Machine:
<http://802.11junk.com/jeffl/WWVB%20test/Time-Machine.jpg>
Black and white wires sticking out of case on the left are the added
data wires.

Time Machine PCB:
<http://802.11junk.com/jeffl/WWVB%20test/Time-Machine-PCB.jpg>

Loopstick antenna:
<http://802.11junk.com/jeffl/WWVB%20test/antenna.jpg>
The Temec chip is under an epoxy blob on the PCB.

Receiver board connections:
<http://802.11junk.com/jeffl/WWVB%20test/connections.jpg>

Signals using a different camera.

Loopstick horizontal and perpendicular to Ft Collins CO:
<http://802.11junk.com/jeffl/WWVB%20test/loopstick-perpendicular-to-WWVB.jpg>
The screen width is 2 seconds or 2 digits wide showing two consecutive
"1" bits.

Loopstick horizontal pointed at Ft Collins CO:
<http://802.11junk.com/jeffl/WWVB%20test/end-pointed-at-WWVB.jpg>
The increased number of transitions are noise. Such a signal will not
decode properly.

Loopstick vertical:
<http://802.11junk.com/jeffl/WWVB%20test/loopstick-vertical.jpg>
Pure noise and no signal.

Bottom line is that the loopstick should be mounted horizontally and
perpendicular to Ft Collins CO. Vertical mounting does NOT work.

[William Sommerwerck]

"Jeff Liebermann" wrote in message

news:10qeq95jchlhr6rhv...@4ax.com...

>> Heath sent one which I reviewed for Elektor. Once it synched

>> up, it worked quite well. Interestingly, I had to replace the
>> carbon trim pots with ceramic trimmers, to get reliable synching.

> I didn't know about that. I'll see if makes a difference on mine.
> Some adjustments might be drifting.

The drift shows up as the unit taking "too long" to sync, or not synching at
all. If you're not having a problem, why waste your time?

When I lived in Bellevue, WA, there was a periodic noise burst that kept the
unit from synching. What it was, I don't know. It might have come from a
traffic-light controller.

[William Sommerwerck]

"Jeff Liebermann" wrote in message

news:1skfq9pr23olbr1e0...@4ax.com...

Loopstick vertical:
<http://802.11junk.com/jeffl/WWVB%20test/loopstick-vertical.jpg>
Pure noise and no signal.

Bottom line is that the loopstick should be mounted horizontally and
perpendicular to Ft Collins CO. Vertical mounting does NOT work.

Interesting. I have the Time Machine and the Time Machine with a projection
clock. With the loopsticks vertical, neither has yet lost sync

That is... the sync annunciator (or what I interpret to be the sync
annunciator) in the display is still visible.

Both show the same time, which is unlikely if either had lost sync.

"Of course" an antenna's orientation should match the signal's. Why the La
Crosse only works when it doesn't, and it doesn't seem to matter for the
Oregon Scientific products -- I don't know.

[Ian Field]

"Arfa Daily" <arfa....@ntlworld.com> wrote in message
news:NsKpv.56803$7m3....@fx11.am4...

All of my desk clocks sync on the hour every hour - my Casio Waveceptor
watch does it every 24h - if it fails it tries again on the hour for the
next 3 or 4 hours.

[Jeff Liebermann]

On Mon, 23 Jun 2014 05:29:50 -0700, "William Sommerwerck"
<grizzle...@comcast.net> wrote:

>"Jeff Liebermann" wrote in message
>news:1skfq9pr23olbr1e0...@4ax.com...
>
>Loopstick vertical:
><http://802.11junk.com/jeffl/WWVB%20test/loopstick-vertical.jpg>
>Pure noise and no signal.
>
>Bottom line is that the loopstick should be mounted horizontally and
>perpendicular to Ft Collins CO. Vertical mounting does NOT work.


>Interesting. I have the Time Machine and the Time Machine with a projection
>clock. With the loopsticks vertical, neither has yet lost sync
>That is... the sync annunciator (or what I interpret to be the sync
>annunciator) in the display is still visible.

I suspect the loss of lock delay is rather long. It would not do to
have the sync indicator flashing on and off as the signal fades in and
out. Besides, the receiver is only powered on for 5 minutes. If you
don't mind tearing it apart, just ground the PON (power on) line, and
monitor the output with an oscilloscope. No need to use the sync
indicator.

Incidentally, with a 1 baud data rate, an LED attached to the data
line should give a tolerable visual indication of signal quality. On
the Temic[1] chip, the output is rather high impedance, so something
like a CMOS buffer will be needed.
<http://psn.quake.net/wwvbsdr.html>
I might modify mine into something like that when I have time.

>Both show the same time, which is unlikely if either had lost sync.

I beg to differ. Reception could be miserable and the sync indicator
probably won't show a problem for 24 hours. I think (not sure) that
it really means that it hasn't received an update for 24 hrs.

>"Of course" an antenna's orientation should match the signal's. Why the La
>Crosse only works when it doesn't, and it doesn't seem to matter for the
>Oregon Scientific products -- I don't know.

I've seen worse RF design mistakes. I couldn't find a teardown of the
WS-811561 or any similar La Crosse radio clock. One possible problem
is that it's impossible to test a WWVB clock in China as the signal
doesn't go that far. It's possible that they designed and tested it
using a simulator, which will not have the cross polarization problem.
Just guessing.


[1] Temic was bought by Atmel in 1998:
<http://www.cpushack.com/2011/02/05/atmel-buys-mhs-again-the-twisted-history-of-atmel-temic-and-mhs/>

[David Harmon]

On Sun, 22 Jun 2014 16:54:40 -0700 in sci.electronics.repair, Jeff
Liebermann <je...@cruzio.com> wrote,

>On Sun, 22 Jun 2014 09:07:46 -0700, "William Sommerwerck"
><grizzle...@comcast.net> wrote:
>
>>Just "Most-Accurate Clock". But it's the same thing.
>
>Heath model GC-1000 I assume.
><https://www.youtube.com/watch?v=c8fD_3MgfDw>
>I have one that I'm "rebuilding". The biggest change is replacing the
>overheating 7805 linear regulator with a switching regulator

We had one of those. We ran coax up two floors to the roof for the
antenna. The shield was grounded at the roof to a drain pipe or
something like one.

The clock ran internally on +5V and +12V supplies. The coax shield
was also connected to the supply ground. In order to get plus and
minus voltages for the RS-232 port, they connected the port ground
pin to the internal +5 supply and switched between +12 and gnd.

We connected the serial port to a PC. The PC serial port ground was
connected to the case, and the third prong on the power cord.
So, we had the clock's +5 supply driving current through a fifty
foot loop of whatever unknown conductors happened to be between that
drain pipe and the third prong.

The 7805 overheated.

>

[Michael Black]

Aren't you in the UK? If so, you have a different time signal, and likely
quite different "atomic clocks". One reason a lot of the clocks here in
North America (and the Waveceptor) try for the signal late at night is
because noise is lower then. Fewer electronic devices on at that point to
make noise. It's variable whether I can get a clock to sync in the
daytime. But if you are in the UK, you'd be closer to the station than
someone like me who is kind of at the outer ring of th reception area for
WWVB, which is in Colorado.

If we're nitpicking about the name, I found on the sidewalk a couple of
years ago a clock that didn't need setting. I got all exicted a desktop
"atomic clock" with LED readout and which ran off the AC line. But it wsa
really misleading, it was set at the factory and had a backup battery or
something, it didn't sync to anything.

Michael

[Ian Field]

"Michael Black" <et...@ncf.ca> wrote in message
news:alpine.LNX.2.02.1...@darkstar.example.org...

The waveceptor can be set up for use in a list of countries, but its a
fiddly process of pressing various buttons in the right order.

The clocks were bought in Lidl and AFAIK mostly German made - so they
probably sync to the 77kHz DCF in Frankfurt rather than the 60kHz MSF in
Anthorn, Cumbria (Formerly sited in Rugby).

[dave]

On 06/23/2014 12:04 PM, Ian Field wrote:
>
>

>
> The waveceptor can be set up for use in a list of countries, but its a
> fiddly process of pressing various buttons in the right order.
>
> The clocks were bought in Lidl and AFAIK mostly German made - so they
> probably sync to the 77kHz DCF in Frankfurt rather than the 60kHz MSF in
> Anthorn, Cumbria (Formerly sited in Rugby).

Isn't GPS a lot less trouble? I'd worry about the elimination of the
leap second if I were you. FYI I have a dozen WWVB clocks of every
description (except 24hr analog).

[Michael Black]

GPS tends to be more expensive. Yes, I got a Garmin used at a garage sale
for five dollars, and then last year a TomTom One for ten dollars at a
Rotary Club sale, but that doesn't happen much. I can get an "atomic
clock" for $20 (or 2.00 for that one at a garage sale), even my Casio
Waveceptor was only $20, some very special deal.

And the Garmin certainly was off a second or so from the "atomic clocks",
so it's back to the old problem of "which is right?". I know the "atomic
clocks" keep the same time, it's so much fun to watch two of them change
time in sync. And, GPS doesn't work so well in a house.

Michael

[Ian Field]

"Michael Black" <et...@ncf.ca> wrote in message
news:alpine.LNX.2.02.1...@darkstar.example.org...

> On Tue, 24 Jun 2014, dave wrote:
>
>> On 06/23/2014 12:04 PM, Ian Field wrote:
>>>
>>>
>>
>>>
>>> The waveceptor can be set up for use in a list of countries, but its a
>>> fiddly process of pressing various buttons in the right order.
>>>
>>> The clocks were bought in Lidl and AFAIK mostly German made - so they
>>> probably sync to the 77kHz DCF in Frankfurt rather than the 60kHz MSF in
>>> Anthorn, Cumbria (Formerly sited in Rugby).
>>
>> Isn't GPS a lot less trouble? I'd worry about the elimination of the leap
>> second if I were you. FYI I have a dozen WWVB clocks of every description
>> (except 24hr analog).
>>
> GPS tends to be more expensive. Yes, I got a Garmin used at a garage sale
> for five dollars, and then last year a TomTom One for ten dollars at a
> Rotary Club sale, but that doesn't happen much. I can get an "atomic
> clock" for $20 (or 2.00 for that one at a garage sale), even my Casio
> Waveceptor was only $20, some very special deal.

When I bought the Casio it was �60, I paid an extra �20 for a stainless
bracelet instead of the extremely nasty "resin" strap, which was probably
what they chose to call PVC.

Last time I saw the price advertised, was touted as a "special offer" in a
newspaper at �145.

[jf...@my-deja.com]

On Tuesday, June 24, 2014 9:38:37 AM UTC-7, Michael Black wrote:
> And the Garmin certainly was off a second or so from the "atomic
> clocks", so it's back to the old problem of "which is right?".

> Michael
After compensating for propaagation delays between my place and Fort Collins, the audiio tone on WWV is good enough for me, and deinitely more reliable than any of my consumer-grade "atomic" clocks decoding WWVB. I do not know how much latency there may be between the process of computer decoding and the LCD display.

[Jeff Liebermann]

On Tue, 24 Jun 2014 12:38:37 -0400, Michael Black <et...@ncf.ca>
wrote:

>GPS tends to be more expensive.

GPS receivers also burn more power making battery life problematic.

12ft GPS Wall Clock
<https://www.sparkfun.com/tutorials/47>

>And the Garmin certainly was off a second or so from the "atomic clocks",
>so it's back to the old problem of "which is right?". I know the "atomic
>clocks" keep the same time, it's so much fun to watch two of them change
>time in sync. And, GPS doesn't work so well in a house.

It depends on what you're trying to accomplish.
<http://leapsecond.com/java/gpsclock.htm>
Note that GPS time is 16 seconds ahead of UTC. There's also UT1 for
astronomers, which is where the leap second originates.

[Geoffrey S. Mendelson]

dave wrote:
>
> Isn't GPS a lot less trouble? I'd worry about the elimination of the
> leap second if I were you. FYI I have a dozen WWVB clocks of every
> description (except 24hr analog).

I've been researching and am looking for old android phones for this
purpose. There is a GPS time setting APP and an NTP app, but they don't
talk to each other.

My goal, which at this point is just speculation, is to put together
a combination APP which converts an old android phone into a GPS based
time server on your wifi network. My hope is if it works and enough people
use it, then not only will people have accurate time on their home networks
without the extra internet traffic, but each one is a bit of old electronics
rescued from a landfill.

To use, you just load the app, connect your phone to AC power and stick it
in a window. It syncs the clock with GPS and makes it available to all
your computers, etc.

If anyone knows of such an app, or wants to write one, feel free to, I
am not looking for anything more than a free timeserver and less trash.

Geoff.

--
Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379

[Jeff Liebermann]

On Wed, 25 Jun 2014 11:50:15 +0000 (UTC), "Geoffrey S. Mendelson"
<g...@mendelson.com> wrote:

>dave wrote:
>>
>> Isn't GPS a lot less trouble? I'd worry about the elimination of the
>> leap second if I were you. FYI I have a dozen WWVB clocks of every
>> description (except 24hr analog).

>I've been researching and am looking for old android phones for this
>purpose. There is a GPS time setting APP and an NTP app, but they don't
>talk to each other.

The wi-fi only Android tablets use NTP to set their clock. Look at:
/etc/gps.conf
for the configuration. Usually, it points to pool.ntp.org.

Incidentally, I had to install a clock sync program on a friends
no-name Chinese Android tablet because it would sync before updating
the date/time, causing the time of last sync to get mangled.
<https://play.google.com/store/apps/details?id=ru.org.amip.ClockSync>

>My goal, which at this point is just speculation, is to put together
>a combination APP which converts an old android phone into a GPS based
>time server on your wifi network.

Using an Android for the platform might be a bad idea. You can easily
find stand alone Linux cards and boxes that will do much the same
thing. For example, Raspberry Pi doing GPS clock:
<http://www.satsignal.eu/ntp/Raspberry-Pi-NTP.html>
Plenty of others with and without GPS for NTP. Incidentally, also
think about stuffing a RADIUS server into the device for Wi-Fi
authentication and security.

Also, why would one use the built in GPS receiver for time, when a
network connected router can deliver the time with reasonable accuracy
via NTP? I don't see the benefit.

>My hope is if it works and enough people
>use it, then not only will people have accurate time on their home networks
>without the extra internet traffic, but each one is a bit of old electronics
>rescued from a landfill.

Well, a noble goal, but I don't think the number of smartphones that
will be saved from the recyclers is going to be noticeably affected by
such a project. A few hundred (or thousand) smartphone NTP/GPS
servers versus 968 million smartphones sold in 2013 (world wide) is
not going to do much.

>To use, you just load the app, connect your phone to AC power and stick it
>in a window. It syncs the clock with GPS and makes it available to all
>your computers, etc.

Not quite so simple. You need to guarantee that your smartphone can
see the sky in order to get the GPS time. You'll need to decide if
the clients gets their time directly from the smartphone (acting as an
NTP server), or 2nd hand from the router as an NTP relay. For
example, Windoze clients by default get their date/time from
time.microsoft.com. Are you going to support SNTP or the full NTP?
Etc.

>If anyone knows of such an app, or wants to write one, feel free to, I
>am not looking for anything more than a free timeserver and less trash.

Sorry, but I don't have the time to do that.

[dave]

I was speaking to the non-compatibility of the VLF clocks across borders
vs a global protocol, for mission critical users with access to the sky.

[dave]

The Baud rate is like 1. I don't think decoding it takes very long.

[dave]

Neat!

[jf...@my-deja.com]

On Thursday, June 26, 2014 7:08:09 AM UTC-7, dave wrote:
> The Baud rate is like 1. I don't think decoding it takes very long.

My "synchronized" atomic clocks sometimes differ by a few seconds with the WWV audio tone.

[Michael A. Terrell]

Jeff Liebermann wrote:
>
> On Tue, 24 Jun 2014 12:38:37 -0400, Michael Black <et...@ncf.ca>
> wrote:
>
> >GPS tends to be more expensive.
>
> GPS receivers also burn more power making battery life problematic.
>
> 12ft GPS Wall Clock
> <https://www.sparkfun.com/tutorials/47>
>
> >And the Garmin certainly was off a second or so from the "atomic clocks",
> >so it's back to the old problem of "which is right?". I know the "atomic
> >clocks" keep the same time, it's so much fun to watch two of them change
> >time in sync. And, GPS doesn't work so well in a house.
>
> It depends on what you're trying to accomplish.
> <http://leapsecond.com/java/gpsclock.htm>
> Note that GPS time is 16 seconds ahead of UTC. There's also UT1 for
> astronomers, which is where the leap second originates.

I have one of these: http://www.ebay.com/itm/331205597628 I have to
get someone to install the antenna for me, since I can no longer climb
ladders.


--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

[Michael A. Terrell]

Arfa Daily wrote:
>
> I'm sure they don't, but most of us on here are engineers of one kind or
> another, and we *do* know better, so we ought not to be helping to
> perpetuate this wrong description ...

Or the imaginary DB9 connectors?

[dave]

You should reorient, you haven't had a lock recently.

[dave]

On 06/27/2014 06:42 AM, Michael A. Terrell wrote:
>
> Arfa Daily wrote:
>>
>> I'm sure they don't, but most of us on here are engineers of one kind or
>> another, and we *do* know better, so we ought not to be helping to
>> perpetuate this wrong description ...
>
>
> Or the imaginary DB9 connectors?
>
>
>

9 pin d-sub

[Tim R]

On Tuesday, June 24, 2014 2:02:04 PM UTC-4, Jeff Liebermann wrote:

> Note that GPS time is 16 seconds ahead of UTC. There's also UT1 for
>
> astronomers, which is where the leap second originates.
>
>

Is this always true? So GPS is precise to the nanosecond, but inaccurate by a quarter minute?

[jf...@my-deja.com]

Maybe, but the little signal strength icon is on solid, and I interpret that to mean it thinks it sucessfully synchronized the last time it tried (less than 24 hours earlier). And I see the discrepancy on all of my cheap WWVB clocks. I do assume that the only significant error in the WWV audio tone is due to the variability of the height of the ionospheric skip layer (this tone was always seems to be in good agreement with my Heathkit GC-1000).

[Jeff Liebermann]

On Fri, 27 Jun 2014 08:02:28 -0700 (PDT), Tim R <timot...@aol.com>
wrote:

That's the difference between relative and absolute accuracy.

The way it works is that time originally had an astronomical
reference, which is based on the earth's rotation. The day was
divided into 24 equal hours, the calendar was divided into 365.25
days, etc. That worked fine as long as you didn't care about too many
decimal places. The problem was that the earth is slowing down 1.7
msec per day every century. There's also irregularities produced by
earthquakes, precession, and relativistic effects due to location and
altitude. In other words, the earth's rotation makes a lousy clock
for everyone except astronomers, who obviously need a clock that
points their instruments to the same place in the sky every time. So,
we have a divergence in time. The astronomy and navigation factions
follows the traditional earth's rotation model, where the length of a
second can vary somewhat. Those building timing instruments assume
that the length of a second is defined in absolute terms by the
vibration of various atoms, and do not change as the earth wobbles
it's way around the sun.

The problems begin when one tries to do celestial navigation with a
sextant using a GPS clock. 1 nautical mile = 1 minute of arc.
Therefore an error of 16 seconds would be 16/60 NM = 0.27 NM = 500
meter error. That's more than enough to miss a harbor entrance or hit
a navigation hazard. I occasionally give demonstrations on how to use
a sextant, and have to constantly remind people to use UTC, not GPS
time. Hint: Your cell phone uses GPS time.
<http://www.zdnet.com/blog/hardware/the-time-displayed-on-most-android-phones-is-wrong/19387>

The 16 seconds might not seem like much, but consider that it started
at zero 34 years ago. Left unchecked, we run the risk of repeating
the mess created by the harmonization of the Julian and Gregorian
calendars, which maintained an 11 day difference until 1752. There
were allegedly rioting in the streets demanding the return of the 11
lost days. Hopefully, that won't happen when UTC and GPS time are
eventually harmonized.

I hope this helps, but if you want a better explanation from the
experts, try the time nuts mailing list and archive:
<http://www.febo.com/pipermail/time-nuts/>

[Tim R]

According to Garmin, GPS time is off by the number of leap seconds that UTC has added, since UTC adds these corrections and GPS does not.

However, a correction signal is sent with the transmission, and if the GPS unit has the proper software it should match UTC to within a second.

So when I get home I'll fire up the eTrex and see if it matches UTC.

[Michael A. Terrell]

dave wrote:

>
> Michael A. Terrell wrote:
> >
> > Or the imaginary DB9 connectors?
>
> 9 pin d-sub

It is a DE9

[Jeff Liebermann]

On Fri, 27 Jun 2014 11:17:55 -0700 (PDT), Tim R <timot...@aol.com>
wrote:

>According to Garmin, GPS time is off by the number of leap seconds
>that UTC has added, since UTC adds these corrections and GPS does not.

Right.

>However, a correction signal is sent with the transmission, and if
>the GPS unit has the proper software it should match UTC to within
>a second.

The problem is that many cell phones and a few GPS receivers don't
bother to include the compensation in sub-frame 4 of the "legacy" L1
C/A navigation message. No clue what happened to that in CNAV-2 or
the current L5-CNAV. I need to RTFM and am too busy/lazy/etc.

>So when I get home I'll fire up the eTrex and see if it matches UTC.

Here's my Droid X2 (Verizon) cell phone versus my Windoze XP clock:
<http://802.11junk.com/jeffl/crud/GPS-vs-UTC.jpg>
I ran a SNTP clock sync on the XP box just before I took the photo. It
shows 15 seconds difference instead of the real 16 seconds. I believe
that's due to latency or round off error in my XP box.

I would not be surprised if later cell phones compensated correctly. I
can dig out some other phones if you want something more current.

Of course, in science, nothing is permanent:
"UTC might be redefined without Leap Seconds"
<http://www.ucolick.org/~sla/leapsecs/>

[Jeff Liebermann]

On Fri, 27 Jun 2014 15:18:17 -0700, Jeff Liebermann <je...@cruzio.com>
wrote:

>>However, a correction signal is sent with the transmission, and if
>>the GPS unit has the proper software it should match UTC to within
>>a second.

Looks like I haven't been paying attention. There's a mess of new GPS
to UPS conversion parameters available on the new L5 frequency that is
just now being turned on.
<http://www.insidegnss.com/node/3986>
It won't do anything for most existing devices because of the lack of
a suitable L5 (1176.45 MHz) receiver. Most smartphones and GPS
receivers only do L1 (1575.42 MHz) and L2 (1227.60 MHz). There are
only a few satellites that transmit on L5 at this time. Lots of other
changes coming:
<http://www.gps.gov/cgsic/meetings/2012/lawrence.pdf>

[Michael A. Terrell]

Jeff Liebermann wrote:
>
> On Fri, 27 Jun 2014 15:18:17 -0700, Jeff Liebermann <je...@cruzio.com>
> wrote:
>
> >>However, a correction signal is sent with the transmission, and if
> >>the GPS unit has the proper software it should match UTC to within
> >>a second.
>
> Looks like I haven't been paying attention. There's a mess of new GPS
> to UPS conversion parameters available on the new L5 frequency that is
> just now being turned on.
> <http://www.insidegnss.com/node/3986>
> It won't do anything for most existing devices because of the lack of
> a suitable L5 (1176.45 MHz) receiver. Most smartphones and GPS
> receivers only do L1 (1575.42 MHz) and L2 (1227.60 MHz). There are
> only a few satellites that transmit on L5 at this time. Lots of other
> changes coming:
> <http://www.gps.gov/cgsic/meetings/2012/lawrence.pdf>

Some photos of the transmitters at WWV, WWVB, and WWVH in a recent
thread on Facebook:

<https://www.facebook.com/groups/transmittersites/permalink/713544682040515/>

[Jeff Liebermann]

On Sun, 29 Jun 2014 21:28:01 -0400, "Michael A. Terrell"
<mike.t...@earthlink.net> wrote:

> Some photos of the transmitters at WWV, WWVB, and WWVH in a recent
>thread on Facebook:
><https://www.facebook.com/groups/transmittersites/permalink/713544682040515/>

Thanks. Very interesting. Note that there are no photos of WWVB on
that page. Only WWV(Ft Colins) and WWVH (Hawaii).

Tiny NIST WWVB pix:
<http://tf.nist.gov/stations/morevbpics.html>
<http://tf.nist.gov/stations/vbpicts.htm>

The big big big cage antenna used for 60 KHz (lowered):
<http://tf.nist.gov/images/radiostations/wwvb-large/art1.jpg>
Kinda difficult to see, so here's my enlarged and tweaked version:
<http://802.11junk.com/jeffl/WWVB%20test/WWVB-antenna-lowered.jpg>
<http://physics.nist.gov/TechAct.Archive/TechAct.99/Div847/Images/fig6.gif>
WWVB uses two transmitters in phase driving each antenna seperately.
Think big.

More photos:
<http://www.panoramio.com/photo/14672442>
<http://www.panoramio.com/photo/960723>

[Brian Gregory]

On 21/06/2014 15:54, William Sommerwerck wrote:
> The current crop of atomic clocks are inexpensive and largely
> disposable. But the following might be of interest.
>
> If the clock refuses to sync, check to see if the ferrite antenna is
> loose and rattling. I've found that if it isn't sitting "vertical", it
> doesn't pick up enough signal.
>
> These clocks generally sync around midnight. But whoever wrote the
> firmware didn't think to attempt a sync when the batteries were
> installed. So if you don't want to wait forever, manually set the clock
> to 11:55 PM (or thereabouts). You should have sync within a few minutes.

Ferrite aerials ALWAYS need to be horizontal with the side of the rod
roughly facing the transmitter.

The correct name for clocks like this is radio controlled.

In regions where the signal controls the change to and from summer time
the normal time these clocks sync themselves is at the time when changes
to and from summer time. 02:00 AM in Europe.
Some may also sync at other times of day in addition to 02:00 AM.

--

Brian Gregory (in the UK).
To email me please remove all the letter vee from my email address.

[Brian Gregory]

GPS doesn't always work indoors.

[William Sommerwerck]

"Brian Gregory" wrote in message
news:wvednQ7Wd4GM8CzO...@giganews.com...

> Ferrite aerials ALWAYS need to be horizontal with the side
> of the rod roughly facing the transmitter.

I agree in principal. But the antenna in my La Cross is vertical. And my
Oregon Scientific clocks work fine with their antennas vertical.

If you like, I can take a photo of the La Cross's internals, and you can see
which way the antenna is oriented.


Since my original post, I've discovered that the La Cross tries to sync at
midnight. The unit sits next to a large-screen TV, so this sync is often
blocked. Once the TV is shut off, the La Cross will almost immediately try to
sync again, regardless of the time.

[William Sommerwerck]

"William Sommerwerck" wrote in message news:lorrd6$mn1$1...@dont-email.me...

> I agree in principal.

Sorry. Forty lashes with a WD-40 coated loopstick! Principle, of course.

[Jeff Liebermann]

On Mon, 30 Jun 2014 07:14:59 -0700, "William Sommerwerck"
<grizzle...@comcast.net> wrote:

>"Brian Gregory" wrote in message
>news:wvednQ7Wd4GM8CzO...@giganews.com...
>
>> Ferrite aerials ALWAYS need to be horizontal with the side
>> of the rod roughly facing the transmitter.
>
>I agree in principal. But the antenna in my La Cross is vertical. And my
>Oregon Scientific clocks work fine with their antennas vertical.

You still don't believe my crude test of antenna orientation?
<http://802.11junk.com/jeffl/WWVB%20test/>

>If you like, I can take a photo of the La Cross's internals, and you can see
>which way the antenna is oriented.

This I would like to see, especially since I can't find any photos
online. I'll trade you.... I'll build up my WWVB module to include a
flashing LED, that should demonstrate the quality of the signal by
flashing regularly at 1 second intervals when there's a good signal,
and flashing much faster and erratically when there's only noise.
<https://www.youtube.com/watch?v=bm5dC5vK0Os>
<https://www.youtube.com/watch?v=cBTsrkPFW2c> [1]
If you want, I'll mail something to you so that can convince yourself.
Now, here's someone that tried it with a vertically mounted loopstick
antenna:
<https://www.youtube.com/watch?v=qicOs6KaX5A>
Notice the rather erratic flashing light pattern. Hmmm...

What I guess(tm) is happening is that you are either in a good
location or have a particularly good loopstick, where the difference
in antenna orientation produces signal level changes from perhaps very
strong, to not so very strong. Therefore, it works in any
orientation. At my location, the signal is not so strong, so the
variation changes from usable, to totally gone.

>Since my original post, I've discovered that the La Cross tries to sync at
>midnight. The unit sits next to a large-screen TV, so this sync is often
>blocked. Once the TV is shut off, the La Cross will almost immediately try to
>sync again, regardless of the time.

I hot wired my Oregon Scientific to run all the time. It burns the
battery a bit more, but I can now see WHEN it will sync by simply
killing the power and waiting for the display to update. It takes
about 5 minutes with a strong signal. After about 9PM PDST, it will
erratically start to sync. After midnight, it's very consistently. I
haven't been up early enough to test when it stops.

WWVB loopstick winding and oscilloscope photos:
<http://www.prc68.com/I/Loop.shtml>


[1] At the very end of the video, notice that the flashing light
pattern changes. That's the 1 minute sync pattern.

[William Sommerwerck]

"Jeff Liebermann" wrote in message
news:nk03r9tu5pdlfodgb...@4ax.com...

>> I agree in principle. But the antenna in my La Cross is vertical. And

>> my Oregon Scientific clocks work fine with their antennas vertical.

> You still don't believe my crude test of antenna orientation?
> http://802.11junk.com/jeffl/WWVB%20test

Why should I disagree with your results?

The fact is that the La Cross antenna is positioned vertically. There's a
sort-of-slot for it, and as shipped, it's hot-glued in place.

>> If you like, I can take a photo of the La Cross's internals,
>> and you can see which way the antenna is oriented.

> This I would like to see, especially since I can't find any photos
> online. I'll trade you...

No trade is needed. Give me a day or two, and I'll send a photo.


> What I guess(tm)...

A man with my sense of humor...

> ...is happening is that you are either in a good location or have a

> particularly good loopstick, where the difference in antenna
> orientation produces signal level changes from perhaps very strong,
> to not so very strong. Therefore, it works in any orientation. At my
> location, the signal is not so strong, so the variation changes from
> usable, to totally gone.

That's plausible. Some things are always true -- except then they're not.

[Geoffrey S. Mendelson]

Brian Gregory wrote:
>
> GPS doesn't always work indoors.
>

Which is why I was looking into turning old Android phones into GPS based
NTP servers. You stick one in a window and it covers (via wifi) your entire
home. :-)

[Michael A. Terrell]

Jeff Liebermann wrote:
>
> On Sun, 29 Jun 2014 21:28:01 -0400, "Michael A. Terrell"
> <mike.t...@earthlink.net> wrote:
>
> > Some photos of the transmitters at WWV, WWVB, and WWVH in a recent
> >thread on Facebook:
> ><https://www.facebook.com/groups/transmittersites/permalink/713544682040515/>
>
> Thanks. Very interesting. Note that there are no photos of WWVB on
> that page. Only WWV(Ft Colins) and WWVH (Hawaii).

Most of the thread has expired. There were links to manuals for the
TMC transmitters that were designed & built for the Navy. There were
several other threads, but I couldn't find any of them.

[Leif Neland]

Geoffrey S. Mendelson sendte dette med sin computer:

> Brian Gregory wrote:
>>
>> GPS doesn't always work indoors.
>>
>
> Which is why I was looking into turning old Android phones into GPS based
> NTP servers. You stick one in a window and it covers (via wifi) your entire
> home. :-)
>

I do not see the point.

If you have wifi, in 99,9% you have internet, and then you can get time
by ntp.

A server or router on your network can most probably be set up to sync
to a server from eg pool.ntp.org and serve ntp for your network.

See http://www.pool.ntp.org for more info.

--
Husk kￜrelys bagpￜ, hvis din bilfabrikant har taget den idiotiske
beslutning at undlade det.

[Geoffrey S. Mendelson]

Leif Neland wrote:
> I do not see the point.
>
> If you have wifi, in 99,9% you have internet, and then you can get time
> by ntp.
>
> A server or router on your network can most probably be set up to sync
> to a server from eg pool.ntp.org and serve ntp for your network.
>
> See http://www.pool.ntp.org for more info.
>

Because NTP costs money to use. Not as in paying NTP servers, but in
eating up bandwidth (many places have very limited UPLOAD bandwith)
and it tends to overload the "atomic clock" (stratum 1) servers.

There is for example, only 1 stratum 1 server in Israel that is not
GPS based, and it is very heavily loaded. So loaded in fact, that
most connections are blocked.

There are no functioning pool servers in the country.

I'm sure Israel is not unqiue, once you get out of the EU, US and maybe
Canada, everyone has the same problem.

[Leif Neland]

Geoffrey S. Mendelson sendte dette med sin computer:

> Leif Neland wrote:
>> I do not see the point.
>>
>> If you have wifi, in 99,9% you have internet, and then you can get time
>> by ntp.
>>
>> A server or router on your network can most probably be set up to sync
>> to a server from eg pool.ntp.org and serve ntp for your network.
>>
>> See http://www.pool.ntp.org for more info.
>>
>
> Because NTP costs money to use. Not as in paying NTP servers, but in
> eating up bandwidth (many places have very limited UPLOAD bandwith)
> and it tends to overload the "atomic clock" (stratum 1) servers.
>
> There is for example, only 1 stratum 1 server in Israel that is not
> GPS based, and it is very heavily loaded. So loaded in fact, that
> most connections are blocked.

You do not need a stratum 1 server

Every university and ISP ought to run a time server of stratum 2 or
more, and join the pool.ntp.org.

As the www.pool.ntp.org says:
"Note that it is not required that your server is a stratum 1 or 2
server - as this project is about load distribution mostly, there is no
reason why a stratum 3 or even stratum 4 server shouldn't join."

[dave]

The earth is slowing down its RPM.

[dave]

On 06/27/2014 09:15 AM, Jeff Liebermann wrote:
> On Fri, 27 Jun 2014 08:02:28 -0700 (PDT), Tim R <timot...@aol.com>

s-is-wrong/19387>
>
> The 16 seconds might not seem like much, but consider that it started
> at zero 34 years ago. Left unchecked, we run the risk of repeating
> the mess created by the harmonization of the Julian and Gregorian
> calendars, which maintained an 11 day difference until 1752. There
> were allegedly rioting in the streets demanding the return of the 11
> lost days. Hopefully, that won't happen when UTC and GPS time are
> eventually harmonized.
>
> I hope this helps, but if you want a better explanation from the
> experts, try the time nuts mailing list and archive:
> <http://www.febo.com/pipermail/time-nuts/>
>

UTC and GPS used to be synchronized but you really can't skip GPS time
because it determines so many other processes. Much easier to get a GPS
clock with a programmable delay and tell the celestial navigators to
update their kit.

[Leif Neland]

Tim R har bragt dette til verden:

The GPS is precise. The earth is inaccurate.

Leif

[Ian Field]

"dave" <rick...@earthlink.net> wrote in message
news:uPadnVSH6cQ5GSTO...@earthlink.com...

Stop the world - I wanna get off.

[Jeff Liebermann]

On Sun, 06 Jul 2014 10:17:24 -0700, dave <rick...@earthlink.net>
wrote:

Too much friction. When that happens, you should lubricate the
bushings on your globe. If that's insufficient, replace them with air
bearings, which should help decrease the rate of slowing.

[Tim R]

On Sunday, July 6, 2014 3:54:07 PM UTC-4, Jeff Liebermann wrote:
> On Sun, 06 Jul 2014 10:17:24 -0700, dave <rick...@earthlink.net>
>
> wrote:
>
>
>
> >On 06/27/2014 08:02 AM, Tim R wrote:
>
>
>
> >> On Tuesday, June 24, 2014 2:02:04 PM UTC-4, Jeff Liebermann wrote:
>
> >>> Note that GPS time is 16 seconds ahead of UTC. There's also UT1 for
>
> >>> astronomers, which is where the leap second originates.
>
>
>
> >> Is this always true? So GPS is precise to the nanosecond, but inaccurate by a quarter minute?
>
>
>
> >The earth is slowing down its RPM.
>
>
>
> Too much friction. When that happens, you should lubricate the
>
> bushings on your globe. If that's insufficient, replace them with air
>
> bearings, which should help decrease the rate of slowing.
>

A magnetic bearing would be great, but that would require the earth have a magnetic field.

Oh wait..............

[Jeff Liebermann]

On Mon, 7 Jul 2014 08:20:52 -0700 (PDT), Tim R <timot...@aol.com>
wrote:

>On Sunday, July 6, 2014 3:54:07 PM UTC-4, Jeff Liebermann wrote:
>> On Sun, 06 Jul 2014 10:17:24 -0700, dave <rick...@earthlink.net>

>>>The earth is slowing down its RPM.

>> Too much friction. When that happens, you should lubricate the
>> bushings on your globe. If that's insufficient, replace them with air
>> bearings, which should help decrease the rate of slowing.

>A magnetic bearing would be great, but that would require the earth have a magnetic field.
>Oh wait..............

No waiting required. Magnetic levity is commonly available:
<https://www.google.com/search?q=magnetically+levitated+globe&tbm=isch>

[William Sommerwerck]

"Jeff Liebermann" wrote in message

news:kdhlr91fqtqrglknf...@4ax.com...

> No waiting required. Magnetic levity is commonly available:
> https://www.google.com/search?q=magnetically+levitated+globe&tbm=isch

What's funny about magnetism?

[Tim R]

I'm shocked you don't get it.

[jf...@my-deja.com]

On Monday, July 7, 2014 9:18:15 AM UTC-7, Jeff Liebermann wrote:
>
> No waiting required. Magnetic levity is commonly available:
>
> <https://www.google.com/search?q=magnetically+levitated+globe&tbm=isch>
>

That's nothing. Andre Geim, winner of the 2010 Nobel Prize in physics for graphene, also won the 2000 Ig Nobel Prize for levitating frogs and mice with magnetic fields.

[Michael A. Terrell]

Jeff Liebermann wrote:
>
> On Sun, 22 Jun 2014 02:10:36 +0100, "Arfa Daily"
> <arfa....@ntlworld.com> wrote:
>
> >> I have another atomic clock with an external antenna. I'll set it up so
> >> it's vertical, and see what happens over the next day or two.
>
> >Surely 'atomic clock' is the wrong term for these devices ? As I understand
> >it, an atomic clock is a laboratory time-standard instrument based on the
> >decay rate of some atomic isotope, usually caesium ? The devices to which
> >you are referring are radio-synchronised clocks (also referred to, again
> >wrongly in my opinion, as "radio controlled clocks" ), deriving their
> >synchronisation from data broadcast from a number of low frequency
> >transmitters around the world. Otherwise, in between the synchronisation
> >times, these clocks are just free-running, much like any other clock.
> >
> >http://en.wikipedia.org/wiki/Atomic_clock
>
> Well, at the end of the WWVB chain, there is a cesium standard
> oscillator feeding the station.
>
> Yep. Even the NIST doesn't like the term.
> WWVB Radio Controlled Clocks: Recommended Practices for Manufacturers
> and Consumers (2009 edition)
> <http://www.nist.gov/customcf/get_pdf.cfm?pub_id=903649>
> See 9.B. Use of "Atomic Clock" Nomenclature Pg 34.
> ... we contend that use of the term "atomic
> clock" is technically incorrect and misleading to
> consumers, and its usage should be avoided. Unless
> there is actually an atomic oscillator inside the
> RCC (such as a cesium or rubidium oscillator), we
> recommend that the term "radio controlled clock"
> be used to correctly describe the product. Labeling
> products or documentation with the term "atomic timekeeping"
> is also considered acceptable.
>
> Good luck stuffing this genie back into the bottle.
>
> Incidentally, the easiest way to check your signal strength is to just
> cram an oscilloscope into the clock module and look at the decoded
> data. This should offer some clues as to what to look for:
> <http://www.leapsecond.com/pages/sony-wwvb/>
> (Note that the loopstick is horizontally mounted.)
> According to the NIST, to obtain reliable updates, the decoded SNR
> should be 20 dB or better. That should be easily visible on a scope
> and what I'll try tonite.


http://www.tmchistory.org/tmc_manuals/tmc_commercial_manual_page.htm has
the manuals for the TMC transmitters used by all the WWV services. They
were designed for the US Navy.